Definition: You are given a question on nutrition. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: Facial flushing is seen in approximately 50% of East Asians and is thought to be due to a deficiency of?

(A)ALDH1 (B)ALDH2 (C)ALDH3 (D)ALDH4

B